Financial support is requested for the XIIth International Symposium on Human Chlamydial Infection. Chlamydia trachomatis infections are the most common bacterial cause of sexually transmitted diseases often resulting in severe pathology in women and newborns. It also increases the risk of HIV infection. C. trachomatis is also the most common infection reported to the Centers for Disease Control and Prevention in the United States. These organisms are also the cause of trachoma, the leading cause of preventable blindness in the world. C. pneumoniae is recognized as a very common respiratory pathogen and the association of C. pneumoniae with chronic respiratory diseases and coronary artery diseases increases the need for understanding these infections. Characterization of the expanded clinical spectrum of chlamydial diseases has been facilitated by advances in molecular techniques for diagnosis. This has been complemented by exciting advances in elucidating the sophisticated interplay between chlamydial organisms and their mammalian host cells and the molecular mechanisms of immunity and pathogenesis. Interest in chlamydial vaccines has been rekindled by advances in this area. Additionally, the information inferred from the recent sequencing of the C. trachomatis and the C. pneumoniae genomes is rapidly providing new insights into fundamental chlamydial biology. This meeting represents the most important gathering for researchers in the field to exchange the highest quality research information. Given the recent explosion of research on chlamydiae, the XIIth International Symposium on Human Chlamydial Infection to be held in June 2010 is particularly needed. This meeting is traditionally held only every four years. It can be expected to uniquely provide the impetus for setting the research agenda on the chlamydiae for the coming years. Page Principal Investigator/Program Director (Last, first, middle): Schachter, Julius, PhD. Project Narrative Chlamydia trachomatis is the world's leading cause of preventable blindness and our most common sexually transmitted bacterial pathogen with serious consequences to affected men, women, and newborn infants. C. pneumoniae is recognized as a very common respiratory pathogen and has been implicated in chronic respiratory disease and coronary artery disease. With recent advances in diagnosis and genomics, it is likely that important advances are imminent and techniques in molecular biology have aided and will continue to help in further characterizing the clinical spectrum of chlamydial diseases. Although no genetic system for these organisms has yet been developed, there have still been recent exciting findings on immunobiology, cell biology, and physiology of chlamydiae. This meeting follows the completion of the sequencing of several chlamydial genomes and the mining of this information in research discovery. With the recent explosion of information on these organisms, the time is right for another in a series of periodic international meetings on the subject. Previous success of these meetings has attested to the value of this venue for exchanging information and comparison of results in different countries. These meetings have continued to provide impetus for new research and represent a singular comprehensive venue for sharing of research findings among and between Chlamydia researchers. One of the important and unique characteristics of this meeting is bringing together a scientific exchange among researchers across disciplines from genetics to clinical trials.